CCL17 and neoplasm: The N2 markers include CCL17, CCL2, Arg, CCL5, and vascular endothelial growth factor (VEGF) (135, 136).The role of transforming growth factor-β (TGF-β) signaling within the tumor microenvironment (TME) has been implicated in the promotion of a pro-tumorigenic neutrophil phenotype (N2) (137).